docs: def results_overall_metrics(self):
          """Overall metrics
  
          Returns
          -------
          dict
              results in a dictionary format
  
          """
  
          if self.overall['Nsys'] != 0:
              accuracy = self.overall['Ncorr'] / float(self.overall['Nsys'])
          else:
              accuracy = None
  
          return {
              'count': self.overall,
              'accuracy': accuracy
          }